Throughout lighting industry and particularly, outdoor lighting such as walkway, flood and spot light applications, it is the desire of manufacturers and of the purchasers and the public that the lighting be reliable with lowest operating cost while meeting safe lighting requirements, require little or no maintenance and have long life. Weather, vandalism, and other factors can adversely affect the life of such fixtures and particularly their lamps and internal power supplies, such as ballasts or transformers.
The heat generated in the fixture itself in both the power supply which may be a transformer operating from typical 115-volt lines to serve low voltage lamps and the lamps themselves generate substantial heat. Heat generated by the fixture itself is a major factor in determining the operating life of the power supply or transformer and the lamp. A notable exception is solar powered lighting, however such systems rarely provide enough light for most applications where safety and reliability are controlling criteria.
The most common solution to the minimization of thermal damage to the key components, the power supply and the lamps in outdoor walkway and other architectural lighting is to provide large thermal conductive bodies such as aluminum housings which act as heat sinks and which sometimes have integral fins to aid in radiating the heat into the surrounding air. Fins, though effective, often detract from the ornamental appearance of the fixture.
An ideal shape for such outdoor walkway and other architectural applications is a cylindrical body, preferably with the power supply toward one end and the lamp assembly at the opposite end. That has given rise to fixtures with a fin section between the two heat sources with the expectation that it will serve to dissipate heat from both sections of the fixture while accepting the appearance of the fins. Examples of various finned fixtures are well known in the art.